In a principal aspect, the present invention relates to a tool for locking two camshafts in a non-rotatable position.
When repairing modem internal combustion engines of the type utilizing dual overhead cams, the camshafts, which activate the cams of the engine associated with the input and exhaust valves, are operative in response to timing gears or belts which rotate the dual camshafts in a precise manner. When attempting to repair a vehicle engine of this type it is desirable, if not necessary, to lock the camshafts in a fixed position relative to the other mechanical parts of the engine.
Various mechanisms have been proposed to effect such locking. For example, Dawson in U.S. Pat. No. 6,332,256 B1 for a Holding Device discloses a tool having four separate holding elements each of which is adjustable so as to engage the sprocket teeth of sprockets associated with the dual camshafts incorporated in the internal combustion engine. An earlier British patent to Dawson GB 230539A for a Device for Holding Rotary Elements, e.g. Engine Timing Belt Sprockets Against Rotation discloses another mechanism for locking the camshaft spurgears or sprockets in position by engaging the teeth of the sprockets and holding them in a non-rotatable position. Learned in U.S. Pat. No. 5,755,029 entitled Dual Overhead Overhead Camshaft Alignment Method depicts yet another tool or apparatus for engaging the sprocket teeth of the camshaft sprockets of an internal combustion engine. Finally, additional patents which show mechanisms of this general nature include Gibbs, U.S. Pat. No. 5,950,294 for a Tool for Immobilizing Camshaft Gears and U.S. Pat. No. 6,058,585 for a Camstopper.
Each of the mentioned references disclose mechanisms which engage the spurgears or teeth of the camshaft sprockets to prevent undesired rotation thereof and to lock the camshafts in a fixed position. Such mechanisms work well, but ultimately require significant adjustment and manipulation in order to become properly engaged with the spurgear teeth. Thus, there has remained a need for an improved mechanism for locking the gears or sprockets associated with a double or dual camshaft arrangement in an internal combustion engine.